2′-trifluoromethyl-substituted aromatic ketones are useful compounds for fine chemicals, raw materials for pharmaceuticals and agrochemicals, raw materials for resins and plastics, electronics and information related materials, optical materials, and the like. 2′-trifluoromethyl-substituted aromatic ketones are useful in industrial applications in a variety of fields.
As for a method of producing a 2′-trifluoromethyl-substituted aromatic ketone, trifluoromethyl benzoyl chloride is, in Japanese Patent Application Laid-Open Publication No. 2009-298715, coupled with ethyl magnesium chloride in the presence of an iron (III)-acetylacetonate catalyst followed by hydrolysis to thereby generate a 2′-trifluoromethyl-substituted aromatic ketone.
The method described in Japanese Patent Application Laid-Open Publication No. 2009-298715, however, uses expensive 2-trifluoromethyl benzoyl chloride (ALDRICH reagent catalog Japan 2012-2014 version: 25,600 yen/25 g) as a raw material and, therefore, the produced 2′-trifluoromethyl-substituted aromatic ketone ends up being expensive.
In Japanese Patent Application Laid-Open Publication No. 2009-102264, trifluoromethyl halogenated benzene is reacted with a vinyl ether in the presence of a palladium catalyst followed by hydrolysis to thereby generate a 2′-trifluoromethyl-substituted aromatic ketone.
The method described in Japanese Patent Application Laid-Open Publication No. 2009-102264 uses an expensive palladium catalyst and expensive DPPP (1,3-bis(diphenylphosphino)propane) as the catalyst's ligand and, therefore, the produced 2′-trifluoromethyl-substituted aromatic ketone ends up being expensive. In addition, it has been difficult to separate the palladium catalyst, the DPPP ligand, and the 2′-trifluoromethyl-substituted aromatic ketone.
In U.S. Pat. No. 5,969,188, trifluoromethyl benzoyl chloride is reacted with a secondary amine to generate trifluoromethyl benzamide as an intermediate. The resultant is reacted with a methylmagnesium Grignard reagent to thereby generate a 2′-trifluoromethyl-substituted aromatic ketone.
Further in U.S. Pat. No. 5,969,188, due to a route in which expensive 2-trifluoromethyl benzoyl chloride (ALDRICH reagent catalog Japan 2012-2014 version: 25,600 yen/25 g) is reacted with a secondary amine to thereby generate trifluoromethyl benzamide which is reacted with a methyl Grignard reagent, the process has been lengthy with operations being complicated. As a result, the obtained 2′-trifluoromethyl-substituted aromatic ketone has been expensive.
The above methods of producing a 2′-trifluoromethyl-substituted aromatic ketone have problems in their industrial use; and inexpensive methods of producing a 2′-trifluoromethyl-substituted aromatic ketone have thus been sought.
It could therefore be helpful to provide an industrially superior method of producing a 2′-trifluoromethyl-substituted aromatic ketone, which method uses inexpensive and readily-obtainable raw materials and exhibits high efficiency of production.